1. Field of the Invention
The present invention relates to a press machine environment, and, more particularly, to a guide system for use in providing slide-type guiding support to a reciprocating dynamic balancer weight.
2. Description of the Related Art
Mechanical presses of the type performing stamping and drawing operations have a conventional construction comprising a crown and a bed portion configured within a frame structure. A slide supported within the frame is adapted for reciprocating movement toward and away from the bed. The slide is driven by a crankshaft having a connecting arm coupled to the slide. These mechanical presses are widely used for a variety of workpiece operations employing a diverse array of die sets, with the press machine varying substantially in size and available tonnage depending upon its intended use.
In a conventional arrangement, the frame structure is formed and/or integrated with a gib apparatus having a known function and configuration. For example, in a typical machine configuration, the frame includes a set of upright support members (e.g., four) extending between the crown and bed at respective corner locations. Transverse cross-beams are used to provide a connection between a pair of same-side uprights. At the upper portion of each upright, a gib member is employed in a known manner to provide guidance-type bearing support to the slide. For example, the gib member includes an engagement surface that is adapted for full surface-to-surface abutting contact with a corresponding surface on the slide or a coupling piece secured to the slide.
Various approaches have been taken to reduce, dampen or otherwise minimize the vibrations generated by the inertial forces associated with the reciprocating movement of the slides and upper dies. In one arrangement, the press machine is adapted to include a balancer mass device that reciprocates in a manner relative to the slide and die configuration so as to counteract the inertial forces generated by the reciprocating slide. In effect, the balancer device serves as a counterbalance against the moving slide. As a result, the vertically-directed inertia forces creating the vibrations are reduced by an opposing vertical inertia force produced by the balancer device, thereby reducing the vibrations.
The balancer device is typically driven by the same rotary components that power the reciprocating movement of the slide, namely, the crankshaft. For this purpose, the crankshaft would include a suitable connection assembly for mounting and otherwise coupling the balancer device to the crankshaft.
As with the slide, the press machine must likewise provide some form of gib-type frame for locating and otherwise guiding the reciprocating movement of the balancer in order to maintain the precise counterbalancing relationship between the slide and balancer device. Any misalignment or disruption in the travel of the balancer device will impair the counterbalancing relationship and thereby diminish its effectiveness in reducing the vibrational activity.
The gib structure for the massive balancer device must be carefully constructed because the same operational and environmental concerns that are addressed in designs for slides gibs are also a factor with balancer gib constructions. For example, thermally-induced clearance close-outs remain a serious issue as it relates to the elimination of clearance spaces between the balancer device and any bearing surfaces of the balancer frame. Otherwise, any undue expansion in the bearing surfaces may cause the frame to interfere with and retard the reciprocating travel of the balancer mass.
A need therefore exists to provide a gib frame for the balancer mass that provides optimal guiding support in terms of minimizing the thermally-induced close-out effect that is potentially experienced by the bearing surfaces.